ImmE6

ImmE6 is an immunity protein produced by E. coli to protect itself from Colicin E6 and its cytotoxic 16s rRNase activity, by binding to the enzymatic C domain and repressing its activity. This occurs to prevent the colicin from killing the cell it is produced in. It is then released when ColE6 binds to BtuB, the outer membrane receptor on the target cell.